Siphon recorder



E. BLAKENEY SIPHON RECORDER May 3l 1927.

Filed Dec. 6, 1921 3 Sheets-Sheet 2 w @QN R om May si, 192'?.

BLNEY sPHoN RECORDER Filed Deo. 6. 1921 3 Sheets-Sheet 3 -WLJULH fTMQU-L.

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ordinarily `obtainable with sible or'high power s fr, la

Patented May 3l, 192122 'NITED STATES EDWARD BLAKENEY,

I OF

0F KITCI-IAWAN, NEW YORK, SSIGNOR T0-RADIO CORPORATION AMERICA, A CORPORATON 0F DELAWARE.

SIPHON RJECRDER Application led December 6, 1921. Serial'lo. 520,27.

4lliis invention relatesto apparatus :for recordingl electric currents and particularly to recording telegruphic or radio signals. "ihe apparatus is especially suited and meets the exacting requirements' di' high speed radio signalling and the objects and operation will therefore be described particularly with reference thereto, as it will be obvious troni such discussion that the arrangement can. be used under other conditions Where the conditions are less severe.

rlfhe cost of equipment, especially transmitting stations for radio signalling7 has been continually increasing7 due to the desire to communicate over greater distances use of an excess of power te secure reliable communication under adverse Weather conditions. .To overcome this and secure profitable 'operation it isdesirable to greatly increase the speed beyond t at manual opera- 'tion und aural reception which is about 2O to Words'per minute. lt is readily postransmitters 'to transmit automatically at speeds of 100 or more words'per minute' and in fact inost such sta: tions are now equipped with relays adapted to 'hendie tliisispced. if the receivers were equipped for higher speeds the transmitters could, it necessery, be built 'for Working at even greater speeds.

'The limitation ot the receiving' speed Ais 4due to' the inet that prompt and ctiicient servico requires almost innnediate transcription7 sothat the duplex receivers and transmitters may immediately' cooperate when any diiiiculty in reading or adjustment is encountered. ln practice it has been found the*L this condi-tion is only realized by aural reception and manuel Llranscription (which is li 'iitod to about 50 Words per minute) sito the best operators or by recording the signals directly in the form oi' e permdnent reward which is at once transcribed by u suitable number of operators. These reiiuirenients are especially pressing in radio signelling because oi diiiiculties, encoun tei-ed in reeding through atmospheric dis- #es7 which, maires it necessary to occa repeat portions ci a message or adie .cceiver or transmitter. l also` desirable to Secure e. device i responds o very sin-all currents so :cessive 2 iicstion with its attendent curieuse .and liculty is avoided.

'moves past the pen Some of the general objects of the inventionwili be apparent from the previous discussion. More particularly the objects of the invention are to decrease the inertia of the moving parts by the construction here-v matter described and particularly by shortening the pen.

Another object of the invention is to proyide en improved ink feeding device which is adapted to cooperate with the shortened inking pen.

it. further object of my invention is to provide means for damping the movements of the pen arm at theends of the pen stroke.

A. still further objectof the invention is to provide e coil :ind magnet'arrangement capable oi giving a considerable movement for small signal current variations.

In accordance with one embodiment of .my invention, l utilize a short tube of small diameter which moves in a slot connectedv to a source ibi? ink supply. The slot and ink supply ere arranged so that the ink is re- ',tained in the slot by its surface tension and the movements of vibratory parts are imparted to the tube which oscillates with one end projecting in the slot and the other end against the recording strip. As the strip it draws ink from the slotthrough the tube. lThe/tulle moves be-y tween the prongs of 'o yieldingy fork which limits the vibratory motion due to the inertia of the pen crm.

The invention, both as to its construction, mode of operation and features of novelty.,- together with tages` thereof, will best be understoodl by reference to the following description taken in connection with the accompanying drawings in which:

Figfl is a plan view ofthe top ci the in strument with portions 'broken away for convenience ci illustration.

Fig. 2 is e, side view with certoinparts in cross section 3 is a detail view showing the slotted ink feed.

Figs. Li and 5 are detail views ot the damp ing device. Fig. 5 .is e diagram showing the effect of the demping' device.

.Referring to the draivingsfas shown in 2, i. utilize u magnetic circuit comprising` e, cylindrical casing l., a base 2, top 3, huving' e central circulerfopeningl 4e and' a further objects and advanl- .Y

central core 5 projecting from the base through the circular opening. In thespace around the core is placed an exciting wind-` i as shown so that in the air space around the upper end of core there exists a uniform radial magnetic field. In view of the large dimensions'of the iron, the small air gap (e. g. /S inch) and the space for the windings obtainable with thisarrangcment I have it possible to secure a powerful magnetic field in the air gap and by placing a coil Which is supplied with the varying currents in this field a considerable pull may be 0btained with very small variations of the current in the coil. The arrangement is therefore applicable to directly recording currents of a value as low as .0005 amperes, so

that the degree of amplification necessary for recording radio signals is', readily ob-Y tained vwithout high expenditures.

Before proceeding to further describe the construction of the arrangement 1t may be sta-ted that any of the usual devices for amplifying radio or tone frequencies may be used together with any present or future imrovements for eliminating, limiting, reducing or otherwise avoiding the effects ofrundesired, natural or artificial disturbances. It is also usually necessary to rectify the current supplied to the recorder -in asuitable'- manner. An ordinary 'telephone may .also

be used in conjunction therewith for listening to quality of the signals.'

The ring shaped moving coil 8 is fitted in the space aroundA the core and consists of .a large number of turns (e. g. 500 to 1000) of very fine silk or enamel covered Wire.

which is held in shape by impregnation, the entire arrangement being adapted to give a. maximum of turns for a given Weight. The coil isuattaehed to a four-prong aluminum spider` 9 of lightweight by means of adhesive material. Electrical connection with the moving coil is made by extending the leads 10, 11 back to dam mg blocks 12, 13, to which the input leads 14, 15'- are also fnstened. To support the coil Without a )preciably adding to its inertia,'four waxe slk threads 16. 17, 18, 19 are attached by adhesive to the four prongs of the aluminum- The threads are each attached at spider. the other end 'to adjusting screws 20.by means of which the coil is properly centered and the tension of the threads adjusted. Near the adjusting screws 20 the threads pass into grooves in the adjustable screws 21 by means of which the height of the coil maybe regulated.

onnection for the marking member is provided by a. vertical aluminum arm 22 having a pin 23 at the upper end which port.

proportionervby means of a screw 29. The adjustment of the lever and spring is facilitated by the `.thumb screw 30 attached to the spring sup- The thuinb screw permits the pen t0 be angularly adjusted so that it bears onithe paper uniformly during its movement-.- The entire assembly is mounted for lateral ad-` justment on a bracket 31 which is fitted on a stud- 32 to which the bracket is clamped by a hand lever 33. This method of support permits the pen arm 24 to be readily t'emoved when repairs or adjustments" are re quired to it or the moving coil suspension.v The portion 34 of the arm 24 on the left of the. pivot is longer than'the portion attached to the spring so that the distance from the support 28, which acts as a f1il- Crum, to the pen is several times the distance from the fulcrum to the point 23 where the moving coil is connected. The

weight of the various members, location off:

the pivot point. .spring fulcrum, tension ofl the coil supports, etc. are all adjus d and so that the pen arm is in suit able position and the movement ofthe end. of the lever 24 is sucient to give a record having convenient variations. A suihble movement is about 1/8 inch.

While the structure described is especially secursuitable for reducing theinerta an A lng a low natural period or high natural frequenc thus enabling small current variations to recorded, another important'feavture of the construction which gives it simplicity, reliability vand sensitiveness is the pen and the/ink feeding arrangement.

nown tyipes of Siphon recorders a glam' tube of smalll iameter is used but'as far as I anr aware the mechanical construction of the re-V corders necessitates bent tubes at least several inches in length dipping vinto an ink reservoir. This adds considerably to the inertia and the'tubes are delicate and difficult to keep in working order. The present construction utilizes a very fine tube 35 ofiglass,

silver or brass which is held in a hole in the lever 24 by wax, adhesive or solder. The tube is straight and need only be about l inch in length, due to the arrangement for feeding the ink and the features of the mechanical construction describedg The lever 24 is adjusted onthe stud so that one end of the pen presses lightly againstthe paper or tube and the other'end moves in a vertical slot 36 in an ink nozzle 37. The vertical slot' .in the ink nozzle is proportioned so as to hold the ink therein due to the surface tension of the ink. The dimensions of this may taching a hose 39 which leads to a reservoir forked at the other end 48.

40. The reservoir is raised and lowered by means of the knob 41 which cooperates with any suitable mechanical movement such as a rack andgear. By trial it is easy to find the maximum height to which the reservoir may be raised without causing the pressure to overcome the surface tension land cause the ink to flow from the slot. 'lhe adjustment is not particularly sensitive and it is not'essential to keep the level of the ink exactly constant. To` facilitate the adjustment ofthe ink feed the nozzle is provided with a slotted portion 42 and clamp 43. The nozzle and pen are arrangedso that the pen enters the. slot about El; to g1g inch and moves freely in the middle of it. .It is found that the rapid movement of the tube in the slot at the rate necessary for high speed recording doesnotvcause the ink to shake out of the slot.

Even with the arrangement as described there'is, ofcourse, some inertia to the moving parts and in consequence the recorder will give some sharp points on the record as shown in Fig. 6. To eliminate these sharp points due to the inertia of the moving parts, a damping device is arranged to cooperate with t e pen. This consists of a substantially balanced damping arm 44. At one end 47 the lever is counterweighted and is The forked end is bent into a position such that the pen arm 24 moves therein. The width of the slot in the fork is sufficient to permit the pen arm' to move freely therein for a distance slightly less than the desired movement of the pen' arm. When the pen arm strikes the damping arm the inertia is overcome and the movement retarded sufficiently to give a flat top. record as shown in Fig. G. Thc damping produced by the arm is controlled by a spring 49 arranged between the arin and a pressure member 50. 'lhe'pressure ineinbei' may be an elastic strip fastened at one end to the support 46 and movable at the other end by means of an adjustable nut 51 cooperating With a threaded stud 52 so that the spring 49 andthe freethe pressure on of the damping arm may doin of movement 1 be varied.

A permanent record is made directly on a strip of paper or'tape.. A guide is .provided for thetape and consists of a brass strip 53 suitably vslotted to provide a narrow passage for the tape which moves in a vertical plane past .the pen which is preferably in the horizontal plane. The passage is open for a short distance near the pen to expose the surface ofthe tape but is covered throughout the balance of its length vby strips 54,` 5.5. 011e end of'tlie guide is attached to a fixed standard 56 and the other e`nd is attached to an adjustable standard 57 cooperating with anhadjusting knob and screw 58, vii. This adjustment permits the tape to be. moved against the paper without disturbinr' the pen. A spring 6() is attached to the guide and presses against the paper in the neighborhood of the pen so'as to keep it tight against the guide.

rThe tape before passing through the guide is preferably passed through a pair of brushes 6l which serve to brush ofi' dust and lint and thus aids in preventing the pen from clogging. Y y

To protect the instrument it is preferably inclosed in a casing 62 having a glass top 63 so that the operation is visible.

In View of the preceding description of the construction detailed discussion of the operation is believed unnecessary. Briefly, however, the operation is as follows: The coil is adjusted to the proper position and the current in the exciting Winding and coil is regulated to give the proper movement of the penv arm. The ink Well and nozzle are adjusted ,so that the the ink in the slot and the nozzle is mo red so that the pen dips in the s lot a short distance. The usual tape feed. pulling motor' such as is'used in the tikker may he util ized for drawing the tape through the 1nl i the elements are adjustable in various ways to facilitate this as well as the assembling and disasseinbling of the structure for replacement or repairs.

As the paper is moved past the pen the ink is drawn therefrom and the flow of ink as well as the movement of the pen has been found satisfactory for recording signals at speeds of 200 words per minute and appareitly can be used for co'nsiderablyhiglier ee s. pThe damping device will .square off the signals but it will be understood that any interfering currents which reach the recorder will also be recorded and will give the rec ord a ragged appearance. If theseinterfering currents are of sufficient 'amplitude the damping device will decrease their effect. on

static. It will therefore be possible for an surface tensionretains llo I experienced operator lto decipherthe signals V` even when considerablestatic. interference esiste, although it will beunderstood that it is highly Adesirable vfor recording radio signals to associate the recorder with the-best i arrangements foi-reducing static interferi `zence.

Sbtained `at the moinentvthe signal is re y receiving operator an opportunity to im` A Well defined permanent record is ceived which may be at once transcribed by the required number of pperators, each of Which will read certain lengths or the tape. The record is then preserved for checking purposes. This type of recorder gives the receiving station immediate and permanent y record at a very low cost and also allows the mediately secure arepeat of any portions of themessage which are missed by having the duplex transmitter request repetition. This; is very conveniently accomplished in modern.

duplex installations in which the receiving operator and transmitting operator are located at the same table in a central station connected by telegraph lines with the re-v ceiving and transmitting station. e

Having described my. invention, what I i claim isl '1. In an indicator forblectric currents, the

.combination f a fluid'reservoir having a slot adapted to retain fluid by surface'tenf Sion and a recording pen movable insaidf slot adapted to Withdraw said fluid from the slot.'

l 2. In an indicator for electric currents, the 'combination of a fluid reservoir having a slot adapted to retain marking `fluid by Surface tension, and a Siphon pen movable in said slot adapted to Withdraw sai'd fluid from the slot.

3'. In an indicator for electric currents, the combination of a fluid reservoir having a vertical Isloty adapted to retain marking Huid tbe'strip.

.bysurface tension and a horizontal Siphon .pen movable in said slot adapted to withshort istance fromsaid slot'and a horizontal Siphon pen having one end movable in "laid, slot bridging the space between 1t and the strip. y 4

'6. Inan indicator for electric currents, the combination of a fluid reservoir having a slot adapted to retain marking fluid by sur- 'marking member,

madamk face tension, a strip of recording tape opposite and spaced a relatively short distance from 'said Slot and a substantially straight siphon pen having an `end movable in said slot bridging the space between it and the strip. i

7 In an indicator vfor electric currents, the combination lof a movable a'rm carryin a a pivoted forked arm etween which the first arm is freely? movable during a portion of its movement and means for varying the freedom of movement of said forked arm.

8. In an indicator for electric current-s.l the couibinaticn of an electro-magnet' having a ring 'shaped air gap, a ring shaped movable coilsuspended in the air gap, a' Siphon pen connected to theA coil and an ink reservoir having a slot adapted to retain fluid by surface tension, said pen being movable in said Slot for withdrawing fluid therefrom.

9. In an indicator for electric currents, the

combination of an electro-magnet having a ring shaped air gap, a ring shaped movable coil suspended in the air gap,'a Siphon pen connected to the coil and an ink reservoir having a slot adapted to retain fluid by surface tension', said pen being movable in Said slot for withdrawing fluid therefrom.

10. In an indicator for electric currents, the combination of an electro-magnet having Va horizontally disposed ring shaped air gap, aring shaped movable coil suspended in the `air gap, a horizontally disposed Siphon pen' vconnected to said coil and an ink reservoir having a vertical slot in which an end of the penisumovable, said slot being adapted to retain marking yfluid by Surface tension and vto supply the pen therewith.

'11. In an indicator for electric currents, the combination of an electro-'magnet having a ring shaped air gap, a ring Shaped movable coil Suspended in the air gap, an

arm connected to said coil, a Siphon pen at tached to said amr and a fluid reservoir having a slot for supplying said pen, said slot being adapted to retain fluid due to the surface tension of the fluid.

.12. In an indicator'for electric currents, l*

the combination of an electro-magnet having a ring shaped air gap, a ring shaped movable coil Suspended in the air gap, a pivoted arm connected to said coil, a recon* ing strip and ink reservoir having a ver 1}- tical slot facing-and 1n close proximity ,t0 j

said strip, Said slot being adapted to retain fluid by surface tension and a tube of small;

diameter attached to said arm and having5 one end movable in said slot and the other end in contact with Said strip. i

13. In an indicator for electric currents, the combination of a primary reservoir for marking. fluid, said reservoir having an opening in a fluid retaining wall, a Secondary reservoir connected with Said primary resarvoir E0 suppiy'marking Huid -herzeo and means for adjusing the height of saif Supplementary reservoir Wi/h respect to said 'irst mentioned 4resem/ nir m adjust he Suid 5 pressulj in a manner TC feed Huid tc said first mgrwni reservoir at a messux'e msuf i'come the surface tension 0I ns. said opening. 14.; In an indicatr foi electric Cmienxs, W the combinatipn of al Huid resehrvoidiiaving an opening in a Huid retaining wail thereof, a reserve, reservoir connected to Said irs, named reservoir to supply marking' Huid thex'eo, the Huid pressure in said reserve reservoir being adjusted in a manner to supply uid tosairi first named reservoi` at a pressure insucient to overcome the surface tension of said iuid across saidopeninlnj.

EDWARD BLAKENY. 

